123 lines
2.7 KiB
Markdown
123 lines
2.7 KiB
Markdown
---
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id: 587d7fa7367417b2b2512bc5
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title: Work with Dynamic Data in D3
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challengeType: 6
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forumTopicId: 301498
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dashedName: work-with-dynamic-data-in-d3
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---
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# --description--
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The last two challenges cover the basics of displaying data dynamically with D3 using the `data()` and `enter()` methods. These methods take a data set and, together with the `append()` method, create a new DOM element for each entry in the data set.
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In the previous challenge, you created a new `h2` element for each item in the `dataset` array, but they all contained the same text, `New Title`. This is because you have not made use of the data that is bound to each of the `h2` elements.
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The D3 `text()` method can take a string or a callback function as an argument:
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```js
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selection.text((d) => d)
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```
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In the example above, the parameter `d` refers to a single entry in the dataset that a selection is bound to.
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Using the current example as context, the first `h2` element is bound to 12, the second `h2` element is bound to 31, the third `h2` element is bound to 22, and so on.
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# --instructions--
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Change the `text()` method so that each `h2` element displays the corresponding value from the `dataset` array with a single space and the string `USD`. For example, the first heading should be `12 USD`.
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# --hints--
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The first `h2` should have the text `12 USD`.
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```js
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assert($('h2').eq(0).text() == '12 USD');
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```
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The second `h2` should have the text `31 USD`.
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```js
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assert($('h2').eq(1).text() == '31 USD');
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```
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The third `h2` should have the text `22 USD`.
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```js
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assert($('h2').eq(2).text() == '22 USD');
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```
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The fourth `h2` should have the text `17 USD`.
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```js
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assert($('h2').eq(3).text() == '17 USD');
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```
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The fifth `h2` should have the text `25 USD`.
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```js
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assert($('h2').eq(4).text() == '25 USD');
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```
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The sixth `h2` should have the text `18 USD`.
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```js
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assert($('h2').eq(5).text() == '18 USD');
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```
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The seventh `h2` should have the text `29 USD`.
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```js
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assert($('h2').eq(6).text() == '29 USD');
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```
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The eighth `h2` should have the text `14 USD`.
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```js
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assert($('h2').eq(7).text() == '14 USD');
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```
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The ninth `h2` should have the text `9 USD`.
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```js
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assert($('h2').eq(8).text() == '9 USD');
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```
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# --seed--
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## --seed-contents--
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```html
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<body>
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<script>
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const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
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d3.select("body").selectAll("h2")
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.data(dataset)
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.enter()
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.append("h2")
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// Add your code below this line
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.text("New Title");
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// Add your code above this line
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</script>
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</body>
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```
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# --solutions--
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```html
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<body>
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<script>
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const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
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d3.select("body").selectAll("h2")
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.data(dataset)
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.enter()
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.append("h2")
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.text((d) => `${d} USD`);
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</script>
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</body>
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```
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